Basic yellow-red dyestuffs of the safranin series and process of making same.



UNITED STATES PATENT oEE1oE.

RUDOLF BUI RCKHARDT, OF BASEL, SWITZERLAND, ASSII IGNOR T0 DURAND & l-IUGUENlN BASIC? YELLOW-RED DYESTUF' SOF THE SAFRANIN SERIES AND PROCESS OF MAKING- SA-ME No Drawing.

To all whom, it may concern.

Be it known that I, RUDOLF. Boner:- HARDT, a citizen of the Swiss Republic, and

resident of Basel, Switzerland, have invented new Basic Yellow-Red Dyestuffs of the Safranin Series and a Process of Making Same, of which the following is a full, clear, and exact specification.

I have found tha'tnew basic yellow-red dyestuffs of the safranin series are obtained by condensing a nitrosomonoalkyl-orthotoluidin with a metaminoalkyl-paratoluidin. These new dy'estufis dissolve in concentrated sulfuric acid to green solutions turning on addition of water firs't'to blue and afterward to red. They give on cotton yellow-red prints and dye with tannin mordanted cotton yellow-red tints.

Example: In a vessel provided with a stirrer and a reflux cooler are mixed-the solutions of.82 kilograms nitrosoethylortho toluidin in 450 litersalcohol and of 50 kilograms ethylmetatoluylenediamin in 450 liters alcohol with 54 kilograms hydrochloric acid of 33 per cent. and slowly heated to boiling. Almost simultaneouslywith the mixing of the substances the reaction begins; the color changes toward green and then passes over blue-violet gradually into .red; After a boiling for 2 hours, no further nitroso compound can be detected in the reaction product, the heating is. suspended and after cooling the dyestufi crystallizes in form of green-golden needles. 'The coloration of its solution in concentrated sulfuric acid is reen and turns on addition of water first to Inc and afterward to red.

The dyestufi corresponds to the formula a k 'm CzHs/l f- H 61- can In an analogous manner can be, prepared the dyestuffs resulting from the condensation of nitroso e ethylorthotoluidin with methyl-meta-toluylenediamin or of nitrosomethylorthotoluidin with ethylmetatoluylenediamin or with methylmetatoluylenediamin. -All four dyestufi s give on cotton yellowred prints and on tannin mordanted cotton yellow-red dyeings.

Specification of Letters. Patent.

ethylorthotoluidin Patented Mar. '7, 1916.

Application filed March 4, 1915. Serial No. 12,098.

The same dyestuffs can be prepared by oxidizing together methylparatoluylenedi- 21mm or ethylparatoluylenediamin with methylmetatoluylenediamin or ethylmetatoluylenediamin.

What I claim is:

1. The described process for the manufacture of yellow-red dyestuffs of the safranin series consisting in condensing a nitrosov alkylorthotoluldm with a metaaminoallrylparatoluidin.

2. The described process for the manufacture of yellow-red dyestuffs of the safranin series consisting in condensing a'nitrosoethylorthotoluidin with a metaaminoalkyl- 'dition of-water first to blue and a terward to red and giving on cotton yellow-red prints and on tannin mordanted cotton yellow-red dyeings.

6. As a new article of manufacture the described yellow-red dyestufi' of the safranin series derived from nitrosoethylorthoto- 'luidin and metaaminoethylparatoluidin, dissolving in' concentrated sulfuric acid to green solutions turning on addition of water first to blue and afterward to red and giving on cotton yellow-red prints and on tannin mordanted cotton yellow-red dyeings.

In Witness whereof I have hereunto signed my name this 16th day of February, 1915, in the presence of two subscribing witnesses.

DR; RUDOLF BURCKHARDT.

Witnesses ARNOLD ZUBER, AMAN BITTER. 

